Hydrogen powered cars have such an immediate and naive appeal. I mean just imagine nothing but water vapour coming out of your exhaust pipe! What could possibly be wrong with that?
Well as with most deus ex machina solutions to our oil dependence, this one has some rather glaring and inconvenient difficulties, in a very similar way to biofuels.
Specifically, the problem with hydrogen powered vehicles is not with the burning of the fuel, but its production. Because there is no earthly source of ready to go hydrogen, this product is actually better thought of as energy storage, rather than an energy source. In other words, it takes a lot of energy to produce hydrogen, energy that is thus stored for later use when it is burned.
However, there is some possible good news I cam across via a Yahoo News article. In a recent paper that appears in the Proceedings of the National Academy of Sciences, the authors describe a new twist on an old method called electrohydrogenesis. Quoting from the news article (not the paper!):
The method used by engineers at Pennsylvania State University however combines electron-generating bacteria and a small electrical charge in a microbial fuel cell to produce hydrogen gas.
Microbial fuel cells work through the action of bacteria which can pass electrons to an anode. The electrons flow from the anode through a wire to the cathode producing an electric current. In the process, the bacteria consume organic matter in the biomass material.
An external jolt of electricity helps generate hydrogen gas at the cathode.
In the past, the process, which is known as electrohydrogenesis, has had poor efficiency rates and low hydrogen yields.
But the researchers at Pennsylvania State University were able to get around these problems by chemically modifying elements of the reactor.
In laboratory experiments, their reactor generated hydrogen gas at nearly 99 percent of the theoretical maximum yield using aetic acid, a common dead-end product of glucose fermentation.
“This process produces 288 percent more energy in hydrogen than the electrical energy that is added in the process,” said Bruce Logan, a professor of environmental engineering at Penn State.
I expect there are many devils in the details, but it certainly seems like an encouraging development.